Wladimir Klitschko has held on to multiple versions of the heavyweight title since 2005.
He has been recognized as the best heavyweight fighter since he knocked out Tony Thompson in 2008. He earned the WBA super heavyweight crown with a 2011 decision over David Haye.
The only possible competition he faces among current heavyweights and super heavyweights is from a man he would never fight, his brother Vitali Klitschko.
The Klitschko brothers have been unyielding and consistent in saying that they would never fight each other in the ring, no matter what the purse or other circumstances.
There's one vote for civility and humanity. Certainly a fight between these two heavyweights would be interesting. It would also be wrong.
Both men have always recognized that.
But what of Vladimir Klitschko's legacy? He is deserving of discussion, if only because he has been a title holder for so long.
His 56-3 record that includes 50 knockouts is worthy of respect. He is a physical giant in the ring, checking in at 6'6" and regularly fighting at 247 pounds.
Klitschko is an impressive specimen and he has dominated the fighters in his era. He can't go back and fight Joe Louis, Rocky Marciano, Muhammad Ali, Joe Frazier, George Foreman or Mike Tyson.
The only thing that can be done is to compare and contrast the styles of the greatest fighters with Klitschko.
He certainly would have the size advantage over any of them, although the "older" version of Foreman certainly had him in the weight category.
But when it comes to boxing skills and fighting styles, it's tough to give Klitschko an edge over any of the greats.
First, look at Klitschko's style.
He is not an aggressive, all-out warrior. In most cases, he has come into the ring with an eye towards protecting himself. He often fights as though he knows he has a vulnerable chin and that a strong two-fisted attack would put him down.
Klitschko's last two defeats were stoppages at the hands of Corrie Sanders and Lamon Brewster in 2003 and 2004. In both of those defeats, he was stunned badly after taking hard punches to the jaw.
The knowledge that he is vulnerable against good but not great heavyweight fighters would probably make him just another opponent for the best heavyweight fighters of all-time.
As many skills as Ali had in the ring—brilliant footwork, scintillating jab, underrated right hand, intelligence in the ring—his ability to fight with courage against vicious opponents like Sonny Liston, Frazier and Foreman may have been what separated him from everyone else.
Louis was probably the most skilled and well-rounded heavyweight of all time and it would be difficult to conceive of Klitschko getting the best of him.
Frazier and Forerman would have been much too aggressive for him. It doesn't seem likely that Klitschko would have gone into fights with either man thinking he was their equal.
Marciano may have been the hardest puncher of the great heavyweights. However, Marciano was 5'11" and 188 pounds. That might have been too much of a height and weight disadvantage for the Brockton Blockbuster to overcome.
Klitschko would seem to have a similar edge over Tyson, who fought his best fights at 5'10" and 218 pounds. But Tyson was so quick, powerful and vicious that he would have gone at the bigger man without any fear.
It might have been a Jack Dempsey-Jess Willard situation.
Klitschko can't be held responsible for the generation that he fought. But his often cautious style indicates a lack of confidence that would have come to the foreground against the heavyweight division's greatest fighters.